490+ Tools Comprehensive Tools for Webmasters, Developers & Site Optimization

File Size Converter

Convert file sizes between different units of measurement.


Understanding File Size Units

File sizes are measured in different units, and understanding the relationship between them is crucial for managing storage, bandwidth, and data transfer.

Decimal vs Binary Units

There are two systems for measuring file sizes:

Decimal Units (SI Standard)

Based on powers of 1000, these units follow the International System of Units (SI):

  • Byte (B): 1 byte = 8 bits
  • Kilobyte (KB): 1,000 bytes
  • Megabyte (MB): 1,000 KB = 1,000,000 bytes
  • Gigabyte (GB): 1,000 MB = 1,000,000,000 bytes
  • Terabyte (TB): 1,000 GB = 1,000,000,000,000 bytes
  • Petabyte (PB): 1,000 TB

Common Use: Hard drive manufacturers, network speeds, storage device marketing

Binary Units (IEC Standard)

Based on powers of 1024, these units are defined by the International Electrotechnical Commission (IEC):

  • Kibibyte (KiB): 1,024 bytes
  • Mebibyte (MiB): 1,024 KiB = 1,048,576 bytes
  • Gibibyte (GiB): 1,024 MiB = 1,073,741,824 bytes
  • Tebibyte (TiB): 1,024 GiB = 1,099,511,627,776 bytes

Common Use: Operating systems, memory (RAM), actual file system calculations

Why the Difference Matters

This is why a 1 TB hard drive shows as only 931 GB in your operating system. The manufacturer uses decimal (1 TB = 1,000,000,000,000 bytes), but your OS uses binary (1 TiB = 1,099,511,627,776 bytes).

Example: 1 TB Hard Drive

Manufacturer (Decimal): 1,000,000,000,000 bytes = 1 TB

Operating System (Binary): 1,000,000,000,000 bytes = 931.32 GiB

Common File Sizes

File Type Typical Size
Text Document 10-100 KB
Email 20-200 KB
Photo (JPEG) 2-12 MB
Photo (RAW) 20-50 MB
MP3 Song (3-4 min) 3-5 MB
HD Movie (1080p) 4-8 GB
4K Movie 20-50 GB
AAA Video Game 50-150 GB

Quick Conversion Reference

Decimal Binary Bytes Difference
1 KB 1 KiB 1,000 vs 1,024 2.4%
1 MB 1 MiB 1,000,000 vs 1,048,576 4.9%
1 GB 1 GiB 1,000,000,000 vs 1,073,741,824 7.4%
1 TB 1 TiB 1,000,000,000,000 vs 1,099,511,627,776 9.95%
Quick Tips
  • 1 KB = 1,000 bytes (decimal)
  • 1 KiB = 1,024 bytes (binary)
  • Each step multiplies by 1,000 (decimal) or 1,024 (binary)
  • The difference grows larger with bigger units